Removal of Methylmercury and Tributyltin (TBT) Using Marine Microorganisms

Abstract

Two marine species of bacteria were isolated that are capable of degrading organometallic contaminants: Pseudomonas balearica, which decomposes methylmercury; and Shewanella putrefaciens, which decomposes tributyltin. P. balearica decomposed 97% of methylmercury (20.0 μg/L) into inorganic mercury after 3 h, while S. putrefaciens decomposed 88% of tributyltin (55.3 μg Sn/L) in real wastewater after 36 h. These data indicate that the two bacteria efficiently decomposed the targeted substances and may be applied to real wastewater.

Biotransformation of tributyltin chloride to less toxic dibutyltin dichloride and monobutyltin trichloride by Klebsiella pneumoniae strain SD9

“…Despite TBTCl toxicity to several organisms, TBTCl resistance has been reported in some bacterial isolates (Wuertz et al, 1991;Fukagawa et al, 1994;Dubey and Roy, 2003;Mimura et al, 2008;Ramachandran and Dubey, 2009;Fukushima et al, 2012;Shamim et al, 2013). Interestingly, there are some reports on marine and estuarine bacterial strains resisting TBTCl and there is evidence suggesting that biodegradation is the major breakdown pathway in estuarine and marine sedimentary environment (Wuertz et al, 1991;Fukagawa et al, 1992;Dubey and Roy, 2003;Mendo et al, 2003;Cruz et al, 2007Cruz et al, , 2010a2014;Lee et al, 2012;Sampath et al, 2012). Bacteria play an important role in biogeochemical cycling along with organic matter degradation and recycling of toxic compounds, including organotins, in estuarine ecosystems (Wuertz et al, 1991;Ayanda et al, 2012;Lee et al, 2012).…”

“…Interestingly, there are some reports on marine and estuarine bacterial strains resisting TBTCl and there is evidence suggesting that biodegradation is the major breakdown pathway in estuarine and marine sedimentary environment (Wuertz et al, 1991;Fukagawa et al, 1992;Dubey and Roy, 2003;Mendo et al, 2003;Cruz et al, 2007Cruz et al, , 2010a2014;Lee et al, 2012;Sampath et al, 2012). Bacteria play an important role in biogeochemical cycling along with organic matter degradation and recycling of toxic compounds, including organotins, in estuarine ecosystems (Wuertz et al, 1991;Ayanda et al, 2012;Lee et al, 2012). TBTClresistant bacteria are able to resist very high levels of TBTCl by employing a number of mechanisms: (a) biotransformation into less toxic di-and mono-butyltins by dealkylation; (b) efflux of TBTCl outside the bacterial cell mediated by efflux pumps; (c) degradation/metabolic utilization of TBTCl as sole carbon source mediated by enzymes; (d) intracellular sequestration and bioaccumulation mediated by metallothionein-like proteins; (e) siderophore production; and (f) alteration in cell morphology (Gadd, 2000;Inoue et al, 2003;Dubey and Roy, 2003;Jude et al, 2004;Sun et al, 2006;Cruz et al, 2007;Ramachandran and Dubey, 2009;Sampath et al, 2012;Shamim et al, 2013).…”

“…Tributyltin was found to be the most abundant among the organotin compounds in the Mandovi and Zuari estuaries (Jadhav et al, 2009;Garg et al, 2010). It has been observed that even at low concentrations TBT in seawater exerts lethal effects on a wide variety of marine organisms (Bryan et al, 1988;Ayanda et al, 2012;Lee et al, 2012). Tributyltin chloride is toxic for both eukaryotes and prokaryotes since with a partition coefficient in octanolewater mixture (log P ow at 25 C) of 3.7, allowing its dissolution into biological membranes, disturbing their integrity, and ultimately disturbing their physiological functions (Jude et al, 2004).…”

Tributyltin Chloride (TBTCl)-Enhanced Exopolysaccharide and Siderophore Production in an Estuarine Alcaligenes faecalis Strain

“…Sorption of TBTCl on humic substances mostly happens in aquatic sediments, which can scavenge most of this organotin compound and serve as an important environmental sink. Among microbes, bacteria play an important role in biogeochemical cycling and toxic organic matter degradation, including that of organotins, in estuarine ecosystems (Wuertz et al 1991;Kawai et al 1998;Gadd 2000;Mendo et al 2003;Suehiro et al 2006;Lee et al 2012;Ayanda et al 2012). Several reports have been documented the isolation and characterization of TBTCl-resistant bacteria from soil, marine, and estuarine environments (Barug 1981;Wuertz et al 1991;Fukagawa et al 1992;Dubey and Roy 2003;Ramachandran and Dubey 2009;Sampath et al 2012).…”

“…It has been observed that even at low concentrations (i.e., 1 to 2 ng Sn/l for Nucella lapillus and Ilyanassa obsoleta), TBTCl in seawater exerts lethal effects on a wide variety of marine organisms and causes immunological, carcinogenic and teratogenic effects on nontarget organisms (Bryan et al 1988(Bryan et al , 1989Sousa et al 2010;Lemos et al 2011;Lee et al 2012;Ayanda et al 2012). The hierarchy of butyltin toxicity is in the following order: TBTCl [ DBTCl 2 [ MBTCl 3 .…”